Tag Archives: depth of field

My Sunday Photo: 5 February 2017

Evening SnowdropsYes, it’s that time of year again – almost spring! I’ve always loved snowdrops, and I probably post a picture a bit like this every year. This time, I’ve given you the whole frame – the image hasn’t been cropped after capture. Also, this picture was taken with a prime (fixed focal length) lens, actually a 100mm macro.
By the time I arrived to take this shot, the winter afternoon light was already fading. I wound up the ISO setting to 3200, selected f/5 and shot at 1/15 of a second – relying on a dose of help from the camera’s shake reduction system!
I’m mentioning this as an example of what I’ve tried to explain before: newer and more expensive equipment won’t improve your skill as a photographer, but what it can do is extend your scope. One particular improvement noticeable on recent camera models, both DSLRs and others, is that good image quality is attainable when using high iso speeds – a great advantage in low light conditions!

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Alphabet Photography Project: B is for Bee

B is for BeeWell… I mean… It’s obvious, isn’t it? Bees are fascinating ¬†and highly photogenic little creatures, and we should all be in a bad way without them. Their contribution to pollination of flowering trees and plants that give us fruit is highly significant!

From time to time, I’ve been asked about how to achieve shots like this, so I shall add a few words on this, here. This shot was taken using an ordinary ‘kit’ lens on my DSLR and the resulting image has been cropped down somewhat. A true ‘macro’ lens, which can focus much closer, would give a potentially better result. However, in either case, the most important issues are to do with focussing and depth of field.
A DSLR, and, indeed many other cameras, will allow you to select the focussing mode. Either select ‘centre spot only’ and aim the focus point at the bee’s eye, or alternatively, switch over to manual focussing, set a close distance (for this lens, the closest possible setting is around 0.25 of a metre) and focus by moving the camera towards or away from the bee (or other small subject) to obtain a sharp focus.
Now, a certain zone, from a little closer to a little further away than the focus point, will give acceptable sharpness. This zone is known as the depth of field. The larger the aperture setting (i.e. the smaller the f number) the more light you will capture, enabling in turn a faster shutter speed to be used. The trade-off, however, is that the depth of field reduces – and in macro photography, the depth of field gets very small, so that only part of the subject is in focus!
We are now tempted to get round this problem by increasing the sensitivity (ISO) setting. The downside here is that this results in a reduction in image quality. Now, here is where the latest models score: they can give very good results at high sensitivity settings (typically ISO 3200) unlike my older model, which starts to show significant degradation of the image above ISO 400. Fortunately, I was blessed with good sunlight on the day this shot was taken!

This picture continues my response to the ‘Alphabet Challenge’.

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Edit by the author, 13 October 2015: today is…


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